CAJ | 학술논문

爱博(Abra)Pb-Cu 矿床位于西澳洲 Bangemall 盆地中,产于中元古界 Edmund 群浅海相碎屑岩地层中,矿体上部呈层状、似层状,下部呈网脉状。由于该矿床地质特征复杂,研究程度不高,矿床成因和成矿流体来源尚存在争议。本文拟探讨成矿流体的性质、来源及演化。流体包裹体显微测温研究表明矿石中石英所捕获的流体包裹体为两相H2O溶液包裹体、含CO2和CH4的流体包裹体、含子矿物三相包裹体等3种类型。上部赤铁碧玉岩段和磁铁石英岩段矿石中流体包裹体均一温度为162.0~194.7℃,盐度为5.8%~13.0%；下部绿泥石化石英砂岩段均一温度为172.7~250.7℃,盐度为7.0%~17.0%。各岩性段中温度和盐度变化都较大,指示有多期流体的存在。锶、硫同位素研究表明：成矿流体为海水与变质水的混合,成矿物质主要来自围岩地层,围岩岩性制约着矿床类型。由盐度和均一温度计算出流体密度为0.885~1.012 g/cm3,成矿深度为0.22~1.39 km,因此确定爱博矿床为一中低温热液矿床。
애박(Abra)Pb-Cu 광상위우서오주 Bangemall 분지중,산우중원고계 Edmund 군천해상쇄설암지층중,광체상부정층상、사층상,하부정망맥상。유우해광상지질특정복잡,연구정도불고,광상성인화성광류체래원상존재쟁의。본문의탐토성광류체적성질、래원급연화。류체포과체현미측온연구표명광석중석영소포획적류체포과체위량상H2O용액포과체、함CO2화CH4적류체포과체、함자광물삼상포과체등3충류형。상부적철벽옥암단화자철석영암단광석중류체포과체균일온도위162.0~194.7℃,염도위5.8%~13.0%；하부록니석화석영사암단균일온도위172.7~250.7℃,염도위7.0%~17.0%。각암성단중온도화염도변화도교대,지시유다기류체적존재。송、류동위소연구표명：성광류체위해수여변질수적혼합,성광물질주요래자위암지층,위암암성제약착광상류형。유염도화균일온도계산출류체밀도위0.885~1.012 g/cm3,성광심도위0.22~1.39 km,인차학정애박광상위일중저온열액광상。
The Abra Pb-Cu deposit was discovered in 1981 in the Bangemall Basin, north-western of Western Australia. The ore body is hosted in the Meso-proterozoic Edmund Group shallow marine clastic sequences. The layered ores present in the upper section, and the veined ores occur in the lower section. Because of its complicated geology and lack of detailed investigations, the genesis of the Abra deposit is debatable. In this paper, the characteristics, origin and evolution of the ore-forming fluid are investigated. Based on the results of micro-thermometry, the fluid-inclusions in the quartz can be divided into three groups: two phases H2O fluid-inclusions, fluid inclusions with CO2 and CH4, and fluid inclusions with mineral crystals. The homogenization temperatures of these fluid inclusions in the upper hematite jasperite and magnetic quartzite vary from 162.0 ℃ to 194.7 ℃, and the salinities vary in the range of 5.8%~13.0% wNaCl; while the homogenization temper-atures of the inclusions in the lower chloritized quartz sandstone vary from 172.7 ℃ to 250.7 ℃, and the salinities vary within the range of 7.0%~17.0%wNaCl. The wide range of homogenization temperatures and salinities in different sections demonstrated that there was more than one phase of ore-forming fluid activities. The data of S and Sr isotopes show that the ore-forming fluid was the mixture of sea water and metamorphic water, and the ore-forming elements were leached from the host strata. And the host rocks have contributed to the ore deposit formation. The calculated densities of the fluid inclusions are from 0.885 g/cm3 to 1.012 g/cm3 based on the homogenization temperatures and salinities. The theoretical ore forming depth is around 0.22 to 1.39 km below the surface, and the Abra deposit can be categorized as a meso-and epithermal deposit.